The answer to 'how to fix drain cleaning' is to first try using a plunger or a drain snake to clear the clog. If that doesn't work, you may need to use a chemical drain cleaner or disassemble the drain to remove the blockage manually. Be sure to wear gloves and eye protection when working with chemicals or disassembling the drain.
Drain cleaning should be done every 6-12 months to prevent clogs from forming. If you're unable to clear the clog or the drain is repeatedly getting blocked, it's best to call a professional plumber to diagnose and fix the issue.